Coupling means for sewer rod

ABSTRACT

Coupling means connect short individual sections of steel rod into a long continuous length of rod for clearing obstructions in underground pipe, sewers and other conduits and provides transmission of applied axial and torque forces from one rod to the next without slippage therebetween and without loss of power.

United States Patent Caperton 1 June 4, 1974 1 COUPLING MEANS FOR SEWER ROD 1.975.244 10/1934 3,480,903 1 1/1969 [76] Inventor: Charles B. Caperton, 52 Pltney 3,617,078 H97, Sprmglake, 07762 3,779,658 12/1973 Cuperton 403/393 [22] Filed: Mar. 1, 1973 Primary lzxamzner-Geo. V. Larkm 1 1 pp NOJ 336,928 Attorney, Agent, or FirmPaul & Paul [52] us. Cl. 403/393 1 1 ABSTRACT [51] Int. Cl. F16b 7/18 Coupling means connect short individual sections of [58] Field of Search 403/393, 308, 339, 340; steel rod into a long continuous length of rod for 15/1043 R, 104.3 SN clearing obstructions in underground pipe, sewers and other conduits and provides transmission of applied [56] References Cited axial and torque forces from one rod to the next with- UNITED STATES PATENTS out slippage therebetween and without loss of powerv 1,170,429 2/1916 Dunlap ..'403/339 X 3 C l aims, 7 Drawing Figures BACKGROUND OF THE INVENTION This invention relates to couplers for connecting to gether short sections of cylindrical spring-steel rod to from a continuous length of rod which may be pushed into a sewer or other pipe or conduit for the purpose of clearing obstructions therein. Each section of rod may, for example, have a length of the order of 39 inches. The continuous length of rod which results from coupling together the short sections may have a length of the order of 900-1 ,000 feet. At the foremost extremity of the coupled rod, a suitable tool is connected for performing a particular clearing operation. Such tool may, for example, be an auger bit, a root saw, a centrifugal cutter or any other of a large variety of tools especially adapted for the purpose. In order for the tool, particularly a cutting tool, to be effective, it is necessary for the coupled rod to be rotated axially. Thus, the couplers must be able to transmit torsional forces from one rod to the next, as well as to transmit axial forces, i.e., push and pull forces.

Couplers have been provided by the prior art, but such couplers have certain disadvantages which will be pointed out. These prior art couplers have two axially spaced holes on opposite sides of its side wall for receiving the terminal ends of the two rod sections which are to be connected together. The rod sections, when coupled, do not physically touch each other. The connection is through the coupler. In order for the terminal end of each rod section to be inserted into the hole in the side wall of the coupler, the short terminal end of the rod must be bent at right angles to its longitudinal axis. This has been possible with spring-steel rod of a diameter of A inch to inch. A demand has arisen, however, for heavier spring-steel rod and the bending at right angles of the terminal of the short terminal end of such rod presents a difficult problem.

SUMMARY OF THE INVENTION A principal object of the present invention is to provide coupling means for sections of spring-steel rod which does not require bending of the short terminal In the present application, the coupling means includes three elements.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a top view, in section, of a presently preferred form of three-element coupling means provided in accordance with the present invention.

FIG. 2 is a side view, in section, looking along the line 2-2 of FIG. I.

FIG. 3 is an exploded view showing the flattened terminal ends of two rods which are to be coupled. to-,

gether.

FIG. 4 is a view, in section, of the left end coupling element seen in FIGS. 1 and 2.

FIG. 5 is an end view, in section, looking along the line 5-5 of FIG. 2.

FIG. 6 is an end view, in section, looking along the line 66 of FIG. 2.

FIG. 7 is an end view, in section, looking along the line 7-7 of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1-7, the terminal ends 12 and 22 of cylindrical rod sections 10 and 20 are flattened, forming the inclined shoulders 17 and 27, as seen most clearly in FIG. 3, and laterally grooved, as at 15 and 25, to form therebeyond the flanges l4 and 24. The flattened, grooved and flanged ends 12 and 22 are thus adapted for interfitting, as indicated by the arrowed dashed lines in FIG. 3, and as seen in side view in FIG. 2

coupler comprises elements 30, 40 and 50, of which element 40 is the center element and elements 30 and 50 are the end elements. Each of the coupler elements 30, 40 and 50 is generally cylindrical. The end elements 30 and 50 have shank portions 35 and 55 which are externally threaded, while the center element 40 is internally threaded at each of its two ends.

As seen best in FIG. 4, end element 30 has a circular through-hole 31, and the shank 35 of element 30 has a circular recess 32, the diameter of which, while larger than that of the through-hole 31, is less than the width of the flattened end portion 12 of the rod section 10. At the inner end of shank 35, two notches 36 are cut, at opposite sides, for receiving the inclined shoulders 17 of the rod section 10.

The other end element 50 has a through hole 51, circular in cross-section for receiving the cylindrical portion of the rod section 20. The shank 55 of element 50 has a recess 52, circular in cross-section. The inward end of shank 55 is beveled forming an inclined shoulder 53 adapted to abut the inclined shoulder 27 of the cylindrical rod section 20.

It will be noted that the flattened ends 12 and 22 of the cylindrical rod sections 10 and 20 will not pass through the circular through holes 31 and 51 of the-end coupler elements 30 and 50. Accordingly, the end elements 30 and 50 are placed on the cylindrical rod sections before the ends are flattened and formed.

To connect the rod sections 10 and 20 together, the flattened, grooved and flanged ends 12 and 22 of the two rod sections are interfitted together, as indicated in FIG. 3 and as also seen in FIG. 2, after which end element 30 is pushed up against the wide flattened end 12 of rod section 10 until the inclined shoulder 17 enters the two notches 36. When this occurs, the element 30 is not thereafter rotatable on the rod section I0.

The center element 40 is then screwed onto the element 30. Center element 40 has a recess 45 which is circular in cross-section and has a diameter corresponding to the width of the flattened ends 12 and 22 of the rod sections. To facilitate screwing the cylindrical center element 40 onto the end element 30, flat surfaces 43 may be provided in opposed positions on the center element.

Finally, the other end element 50 is screwed into the center element 40 until the inclined shoulder 53 of the shank of element 50 abuts against the shoulder 27 of the rod section 20.

Referring now to FIGS. 1 and 2, the three-element 3 By the three-element Coupling means just described, the interfitted ends of the coupled rod sections and are held together. Torsional and axial forces applied to one of the rod sections will be transmitted to the other rod section without loss. For example, if torsional forces are applied to rod section 10, such forces will be transmitted through the interfitted flattened ends 22 and 12 to the other rod section 20. Similarly, if an axial force, in either the push or pull direction, is applied to either of the rod sections, such force will be transmitted to the other rod section through the clamped-together interfitted ends 12 and 22.

While the coupler element 40 has been illustrated as having a center recess 45 of circular cross-section, which is a preferable shape for cost-of-manufacture reasons, it is to be understood that so far as operability is concerned the recess 45 of the center element 40 may be rectangular with dimensions corresponding to those of the flattened interfitted ends 12 and 22 of the rod sections.

What is claimed is:

l. in combination:

a. first and second cylindrical metal rod sections,

a-l. each rod section having its end portions flattened and spread to form inclined shoulders at the junction of the end portion with the cylindrical portion of said rod section,

a-2. each rod section having its flattened ends grooved laterally inward of the end of the rod section to form a terminal flange, the terminal flange of said first rod section fitting into the groove of the second rod section and the terminal flange of the second rod section fitting into the groove of the first rod section when said sections are intcrfitted together in overlapping manner;

. 4 bfco'upliii'g means for connecting said rod sections axially together in overlapping manner for transmitting axial and torsional forces from one rod section to an adjacent rod section without substantial loss, said coupling means comprising;

b-l. first, second and third coupler elements,

b-2. said first coupler element having'an externally threaded shank having an internal recess, said shank having inclined shoulders at its inward end for bearing against said inclined shoulders of said first rod section,

b-3. said second coupler element being internally threaded at both ends, and adapted at one end to be screwed onto the shank of said first coupler element, said second coupler element having a center recess having a cross-sectional dimension corresponding to that of the flattened and spread end portions of said rod sections,

b-4. said third coupler element having an externally threaded shank adapted to be screwed into the other end of said second coupler element, said shank having an inclined internal shoulder for abutting against the inclined shoulders of said second rod section.

2. The combination according to claim 1 wherein said center recess of said second coupler element is of circular cross-section having a diameter corresponding to the width of the flattened end portions of said rod sections.

3. The combination according to claim 2 wherein said inclined shoulders at the inward end of said shank of first coupler element are in a pair of spaced-apart notches. 

1. In combination: a. first and second cylindrical metal rod sections, a-1. each rod section having its end portions flattened and spread to form inclined shoulders at the junction of the end portion with the cylindrical portion of said rod section; a-2. each rod section having its flattened ends grooved laterally inward of the end of the rod section to form a terminal flange, the terminal flange of said first rod section fitting into the groove of the second rod section and the terminal flange of the second rod section fitting into the groove of the first rod section when said sections are interfitted together in overlapping manner; b. coupling means for connecting said rod sections axially together in overlapping manner for transmitting axial and torsional forces from one rod section to an adjacent rod section without substantial loss, said coupling means comprising; b-1. first, second and third coupler elements, b-2. said first coupler element having an externally threaded shank having an internal recess, said shank having inclined shoulders at its inward end for bearing against said inclined shoulders of said first rod section, b-3. said second coupler element being internally threaded at both ends, and adapted at one end to be screwed onto the shank of said first coupler element, said second coupler element having a center recess having a cross-sectional dimension corresponding to that of the flattened and spread end portions of said rod sections, b-4. said third coupler element having an externally threaded shank adapted to be screwed into the other end of said second coupler element, said shank having an inclined internal shoulder for abutting against the inclined shoulders of said second rod section.
 2. The combination according to claim 1 wherein said center recess of said second coupler element is of circular cross-section having a diameter corresponding to the width of the flattened end portions of said rod sections.
 3. The combination according to claim 2 wherein said inclined shoulders at the inward end of said shank of first coupler element are in a pair of spaced-apart notches. 